Woodworking machine



Patented Oct. 17, 1933 UNITED STATES WOODWORKING MACHINE Arvid Stenberg,

Nassjo, Sweden,

assignor t Aktiebolaget Sigfr. Stenberg & 00., Nassjo,

Sweden 7 Application November 21, 1932, Serial No. 643,724, and in Sweden November 23, 1931 10 Claims.

This invention refers to wood working machines and more particularly to mortising machines adapted to cut holes of a rectangular cross section. For cutting such holes boring or milling machines were heretofore used having a rotating cutter movable in the longitudinal direction of the hole to cut a hole having rounded ends or corners. It was then necessary to out said rounded ends or corners to right angles, either by hand or by use of machines particularly constructed for that purpose. Thus, the cutting of an oblong, orthogonal hole or recess heretofore required at least two steps of operation, which means a waste of time and a lack of accuracy.

The chief purpose of this invention is to make it possible to out such rectangular holes or recesses in one single stroke of the machine i. e. in one single step of operation.

A further object of this invention is to out such holes much more rapidly than heretofore without any complication of the 'machine or rather with some simplification of the same.

A further object of this invention is to out such holes having a rectangular cross section, for instance mortises, to'exactly the right shape and to cause the cutting tools to cooperate in such manner that they always have the right position in relation to each other so as to give exactly the desired form. In the machines heretofore used for cutting rectangular holes in two steps of operation it is very diflicult to have the milling cutter or the drill and the irons or chisels cutting the orthogonal corners to cooperate in such manner that the hole really becomes rectangular, because the chisels may easily be displaced somewhat when fed forwards for working and thus, make a false cut. Other purposes will be evident from the following specification and claims.

One embodiment of the invention is illustrated in the annexed drawing.

Fig. 1 shows an elevation of a wood working machine embodying this invention. Fig. 2 shows a plane of the same machine.

Fig. 3 shows a plan of the eccentric .device on a larger scale.

Fig. 4 shows a cross section on the line IV-IV in Fig. 3 through the eccentric disc having a variable eccentricity. Y Fig. 5 shows a hole having round corners or ends, such as cut by the drill or rotating cutter alone.

Fig. 6 shows a correspondingview in which those portions are marked in black which are to be cut away by the chisels.

Referring now to the drawing 1 indicates a stationary base plate having a standard 2 secured thereto. The standard 2 is in plan view L-shaped as illustrated.

The standard 2 carries a stationary bracket 3 forming a bearing for a vertical shaft 4, which carries a fork-shaped support 5 having two bearings 6 for a horizontal tool shaft '7.

Said shaft carries a chuck 8 in which a rotary drill or milling cutter 9 may be clamped in wellknown manner. Furthermore, said shaft 7 carries a belt pulley 10, which has the shape of a body of rotation generated by a rotating concavecurve, as shown. On said pulley and a second pulley 11 a belt 12 runs. The pulley 11 is secured on the shaft of an electric motor 13 secured to the base plate 1.

To the fork-shaped'support 5 a projection 14 issecured which is, preferably, integral with said support. By means of a journal or pin 15 a rod 16 is articulately connected with the projection 14. The other end of said rod 16 is journalled on a pin 17 secured on a slide 18 (Figs. 3 and 4), which is movable in a slot or guide 19 in a disc 20 which is secured on a rotatable shaft 21, journalled in a bracket 22 on the standard 2. A screw 23 is journalled in said disc along said slot 19 engages the slide 18, which may thus be moved to and secured in any desired position along the slot 19. The screw 23 may be rotated by means of a wrench or the like placed on a square on either end of the screw 23 in wellknown manner. It is evident that the position of the pin 17 in relation to the shaft 21 determines the eccentricity of the eccentric mechanism 16, 17,20, 21.

The shaft 21 is via a bevel gear 24 driven by a shaft 25 journalled in a bearing 26 on the standard 2. Said shaft 25 carries a step pulley 2'7 and another step pulley 28 is secured on the shaft ofthe electric motor 13. A belt 29 runs on the two pulleys 2'7, 28.

On the shaft 21 a cam disc 30 is secured which v actuates a rod 31, which is articulately connected with a pawl 32 engaging a ratchetwheel 33 on a shaft 34. Said shaft 34 carries at its other end a hand wheel 35 and is rotatably journalled in a table 36. In guides 37 on said table a work holder 38 is slidable at right angles to the shaft 34. The work holder 38 carries a toothed rack 39 meshing with a toothed wheel 40, secured on the shaft 34. It is evident that upon turning the shaft 34 either by means of the hand wheel 35 or the ratchet wheel 33 the work holder is moved to or from the cutter 9. The table 36 is slidable in vertical guides 41 on the standard 2 and may be raised and lowered by means of a handle 42, actuating, for instance, a screw mechanism for moving the table 36 in the vertical direction, in well-known manner. In the embodiment shown the hand wheel 42 is via a bevel gear 43 connected with a vertical screw spindle 44, engaging a threaded hole in the slide table 36 to lower or raise said table when the handle 42 is turned in the corresponding direction. By means of the hand wheels 35 and 42 it is thus possible to raise and lower the work holder 38 and to feed it to and from the tool 9. a

In horizontal guides 45 on the standard 2 two slides 46 are slidable, which are provided with threaded bores engaged by the two parts 47 and 48 of a screw, which is rotatably but not slidably journalled on the standard 2 and may be rotated by means of a hand wheel 49. The part 47 of the screw is left-handed, while the part 48 has a right-handed thread. It is obvious, that upon turning the hand wheel 49 the two slides 46 will be pushed together or apart. On said slides 46 chisels 50 are secured by means of bolts 51. The chisels 50 at a level with the cutter 9 and have the same width as the diameter of said cutter.

The device described acts as follows:

The motor 13 drives via the belts l2 and 29 the shafts 'i and 25. The tool shaft '7 gives the cutter arotary motion around its axis, while the shaft 25 drives the eccentric device 15, 16, 17, which in its turn gives the fork-shaped support 5 a rocking motion around the shaft 4. Thus, the rotary cutter 9 will have a rocking or pendular motion in a horizontal plane.

A work piece is placed in the correct position on the work holder 38 and, preferably, clamped to the same by means of well-known clamping devices, such as jaws or clamping bolts. Then the table 36 is raised or lowered vertically to the desired position by means of the hand wheel 42 and fed towards the cutting tools 9 and 50 by means of the hand wheel 35 or the ratchet wheel 33, driven from the shaft 21 in the manner described above. Thus, the tools 9 and 50 will cut a rectangular hole or mortise in the work piece at the proper place. The cutter 9 swinging in the plane of the chisels 50 will cut a hole having round ends or corners, as shown in Fig. 5, while the chisels will out said corners to right angles as shown inFig. 6, in which the portions to be cut away by the chisels are indicated in black. The length of the hole cut may be varied to-any desired value by turning the handle 49 to move the chisels apart or together. Afterthe chisels thus have been set, the stroke or amplitude of the cutter 9 is correspondingly adjusted by adjusting the eccentricity of the eccentric device 15, 17, 20, 21 by means of the screw 23 in the manner described above. For varying the width of the holes out new chisels having the desired width and a new cutter 9 having the same diameter as said width are inserted instead of those previously used.

The particular shape of the pulley 10 makes it possible to have said pulley swing in the manner described above, while properly driving the tool 9. As the pulley 10 is swung or oscillated the belt 11 will run accordingly on a lower or a higher part of the pulley l0 and thus, the belt 12 is always stretched to the proper degree. It is not possible to substitute a belt pulley of the usual convex shape for the pulley 10 shown.

The device described having the work piece fed against the stationary tools is generally preferable, because it is easier to drive the milling cutter in this case. It is, however, possible to clamp the work piece to a stationary table and to feed the chisels 50 and the cutter 9 towards the stationary work piece by means of suitable devices, analogous to those indicated by the reference characters 32-44; Generally, it is necessary that the working tool and the work piece shall be able to be moved in three dimensions in relation to each other and for this purpose, either the work piece or the working tool may be moved in one, two or three dimensions or directions and the other be moved in two or one directions or be stationary, respectively, as is Well-known from working machines. In the embodiment shown the necessary motion in the direction of the shaft 34 is effected by displacing the work piece by hand on the table 38 before clamping it.

The milling cutter or drill 9 need not perform a rocking movement during the cutting operation but may be moved or oscillated parallel to itself in the longitudinal direction of the hole to be cut, as is well-known in milling machines for cutting slots and oblong holes.

WhatI claim is:-

1. In a wood working machine, in combination, a rotatable cutter, means for oscillating said cutter in a plane, cutting irons at the ends of the path of the oscillating motion of said cutter, a common support for said cutter and said cutting irons, a work holder, and means for movingsaid cutter and said cutting irons simultaneously in relation to said work holder to cut a hole having a rectangular cross section in one single opera.- tion.

2. In a wood working machine, in combination, a rotatable cutter, a chuck for said cutter rotatably journalled in bearings rockable on a common support, cutting chisels adjustably secured to said support on both sides of said cutter, means for rocking said chuck to and fro, a work holder, and means for moving said common support-and said work holder in relation to each otherito cause said cutter and said chisels to cute. rec-1 tangular hole in one single operation. a

3. In a wood working machine, in combination, a common support, a carrier rockably. journalled in said support, a chuck rotatably journalled in said carrier, a cutting tool in said. chuck, a drive ing eccentric connected with said carrier to rock it to and fro, cutting chisels on said common support having a width substantially equal to the diameter of said cutting tool,.and a work holder movable in relation to said common sup port to cause said cutting tool and said chisels to cut simultaneously a. rectangularv hole in a. work piece on said work holder. I

4. 111 a Wood working machine, in combination, a common support, a rockable carrier on said support, a rotatable chuck on said carrier, .a spiral drill in said chuck, a drivingeccentric actuating said carrier-to cause said cutter to oscillate, the eccentricity of said'eccentricbeing adjustable, adjustable cutting chisels on said common support having a width substantially equal to the'diameter of said spiral drill, anda. work holder movable in relation to said 'comnions'upport to cause said spiral drill and said chisels to cut' simultaneously a rectangular hole in a wooden work piece on said work holder.

5. In a wood working machine, in combination, a'rotatable cutter,.means for oscillating said cutter in one plane, cuttingirons at the ends of the path of oscillating motion of said -cut'ter,.a stationary common support for said cutter and said cutting irons, a work holder movable in relation to said stationary common support to enable said cutter and said cutting iron to out, in one single operation, a hole of a rectangular cross section in a wooden work piece clamped to said work holder.

6. In a wood working machine, in combination, a stationary standard, a fork journalled in said standard, a tool shaft journalled in said fork, a chuck secured on said tool shaft, a cutter in said chuck, a belt pulley on said tool shaft having a surface of rotation generated by a concave curve, a driving pulley, a belt on said two pulleys, a rod articulately connected with said fork, an eccentric connected with said rod, a driving shaft for said eccentric, cutting chisels on said stationary standard, a work holder, and means for moving said work holder in relation to said standard to cause said cutter and said chisels to cut a rectangular hole in one single operation in a wooden work piece on said work holder.

'7. In a wood working machine, in combination, a stationary frame, a rockable support journalled in said frame, a tool shaft rotatably journalled in said support, a cutter carried by said tool shaft, a belt pulley on said tool shaft having a surface of rotation generated by a concave curve, a rod articulately connected with said rock-able support, an eccentric with variable eccentricity connected with said rod, a driving shaft for said eccentric, a pulley on said driving shaft, a motor having pulleys with belts for driving said concave pulley and said other pulley, cutting chisels on said stationary standard, a work holder, and means for moving said work holder in relation to said standard to cause said cutter and said chisels to cut a rectangular hole in one single operation in a wooden work piece on said work holder.

8. In a wood working machine, in combination, a rotatable cutter, means for oscillating said cutter in one plane with an adjustable amplitude, a common support carrying said cutter, a screw rotatably but not slidably journalled on said common support and provided with one right-handed and one left-handed thread, guided slides on said threads, cutting chisels secured to said slides in the plane of the reciprocating motion of said cutter, means for rotating said screw, and a work holder movable in relation to said common support to cause said cutter and said chisels to cut in one single operation a mortise of rectangular cross-section in a wooden work piece on said work holder.

9. In a wood working machine, in combination, a stationary frame, a support rockably ournalled in said frame, a driven tool shaft rotatably journalled in said support, a chuck on said tool shaft, a cutter in said chuck, a rod articulately connected with said support, a second driven shaft in said frame, a disc on said second driven shaft, a slot in said disc, a pin adjustable to different positions in said slot and connected with said rod, a screw having one right-handed and one left-handed thread rotatably but not slidably journalled in said stationary frame, guides in said frame, two slides in said guides, threaded bores in said slides engaging said threads of said screw, a handle secured on said screw to rotate the same, chisels secured to said slides on both sides of saidcutter, and a work holder movable in relation to said stationary frame to cause said cutter and said chisels to cut simultaneously an oblong rectangular hole in one single operation in a wooden work piece on said Work holder.

10. In a wood working machine, in combination, a rotatable cutter, means for reciprocating said cutter in a plane, chisels at the ends of the path of the reciprocating motion of said cutter, a stationary standard carrying said cutter and said chisels, a work holder movable in relation to said stationary standard, and an automatic feeding device for said work holder to move said work holder towards said cutter and said chisels to cause them to cut an oblong rectangular mortise in a work piece on said work holder in one single feeding stroke.

ARVID STENBERG. 

